Unite will now meet with cabin crew representatives on Monday to discuss the next moves in the dispute, which could include possible strike dates.

The union’s joint general secretaries, Derek Simpson and Tony Woodley, said: “BA management should take note of their own employees’ strong rejection of their offer and immediately address the outstanding concerns.

“They should make no mistake that Unite is fully committed to supporting our members in furthering this dispute if no resolution is found.”

The continuing dispute was sparked by a row over staff numbers, working conditions and pay.

A spokesman for BA said: “British Airways is disappointed but not surprised that Unite has clearly orchestrated a rejection of a very fair offer that addresses all the concerns raised during 14 months of talks.

“We urge Unite to put an end to this unnecessary dispute and focus on the best interests of its members. There can be nothing positive to be gained from further strikes.”

The airline added it was “not too late for Unite to put and end to this dispute”.